Organisms such as barnacles, mussels and algae are likely to adhere on ships, fish nets, and other in-water structures. Such adhesion of organisms will lead the problem of hindrance of efficient travel and waste of the fuel in ships and the like. In fish nets and the like, the problems of clogging and shortening of the service life arise. Conventionally, for preventing adhesion of organisms to these in-water structures, a measure of applying an antifouling paint on surfaces of an in-water structure has been taken.
As the above antifouling paint, an antifouling paint containing a hydrolyzable resin having a hydrolyzable group such as a metal-atom-containing group in a resin side chain as a binder resin (vehicle) is recently used because in such an antifouling paint, the antifouling film surface is gradually self-polished by hydrolysis by being dipped in water, and as a result, an antifouling effect can be exerted for a long period of time [for example, Patent Literature 1 (Japanese Patent Laying-Open No. 62-57464), Patent Literature 2 (Japanese Patent Laying-Open No. 10-298455) and Patent Literature 3 (Japanese Patent Laying-Open No. 2001-342432)]. However, in the conventional antifouling paint, it is necessary to separately blend a large amount of antifouling agent for exerting an antifouling effect for a long period of time.
In order to solve these problems, for example, in Patent Literature 4 (Japanese Patent Laying-Open No. 2004-300410) and Patent Literature 5 (Japanese Patent Laying-Open No. 2004-307816), there are proposed antifouling coating compositions containing, as a vehicle, a copolymer containing a polymerizable monomer unit containing (meth)acryl-modified silicon at one terminal and/or both terminals and a metal-atom-containing polymerizable monomer unit containing a divalent metal atom. However, coating films formed from the antifouling coating compositions described in Patent Literature 4 and Patent Literature 5 are insufficient in crack resistance, and the coating films can be cracked by being dipped in water (sea water or the like) for a long period of time, or under an environment where drying and wetting are repeated, although they exhibit an excellent antifouling property.